Whale vocalizations are the sounds used by whales for different kinds of communication. Sounds are produced by cetaceans for various purposes by several different mechanisms. Toothed whales produce rapid bursts of high-frequency clicks that are thought to be primarily for echolocation, while the complex sounds of the humpback whale (and some blue whales) are believed to be primarily used in sexual selection. This young humpback whale is singing in the waters of Vavaʻu, Tonga.Credit: Sylke Rohrlach